BRENTWOOD — The estranged wife of a Manchester police officer testified that she was body slammed by her husband and suffered bruising to her upper thigh and right arm for confronting him about a secret email account he used to exchange photos with other women.

Nathan Robert Linstad, 35, formerly of Raymond, went on trial Tuesday in Rockingham County Superior Court for misdemeanor simple assault.

Assistant County Attorney Patricia Conway said during opening statements that an argument at the couple’s Raymond home quickly grew physical when Linstad put his wife in a bear hug from behind and slammed her to the ground.

“She didn’t brace herself. She had no idea it was coming,” Conway said.

The alleged attack happened in front of the couple’s 5-year-old son. Linstad then warned his wife not to call the police, according to prosecutors.

“‘Do not call the police because if you do I will get arrested. I will lose my job and you will end up with nothing.’ Those were the defendant’s words after he assaulted his wife on Sept. 5, 2012,” Conway said.

Defense lawyer Eric Wilson told jurors that Linstad adamantly denied ever assaulting his wife and that it would become apparent during the trial that his client’s marriage was dissolving long before the confrontation in September.

“I thought we were in divorce court when we heard how bad Nate Linstad is,” Wilson said. “I’m not going to ask you to like that he was emailing other women. But that’s not what we are here to decide.”

Melinda Linstad testified that days before the assault, her husband sent her a text message at work to say that he wasn’t happy. That prompted her to go home, where her husband told her that he didn’t love her anymore, according to her testimony.

Melinda Linstad said she questioned her husband whether there was another woman, but he denied there was anyone else. Once she discovered his email address, he later confessed that, “he was sending pictures to women while he was working his late night details,” she testified.

Nathan Linstad admitted that he had been exchanging photos with other women since their 5-year-old son had been born, and that “these girls didn’t mean anything to him,” Melinda Linstad testified.

“He called them turds — girls from the club who would send naked pictures of themselves and he would send pictures back,” she told jurors.

The email account he was using for the exchanges — badge26 — was discovered by Melinda Linstad late one night from checking their phone bill, according to prosecutors.

Melinda Linstad testified that despite the problems, she wanted to save her marriage and sought counseling.

“When I got married, I took a vow to love him for better or for worse,” Melinda Linstad testified. “I have two sets of grandparents who had been married for over 60 years and it was something we were brought up to believe.”

She testified that she believed her husband might have been suffering from post-traumatic stress disorder because her husband’s former partner, Michael Briggs, had been shot and killed in the line of duty in October 2006.

Nathan and Melinda Linstad married in December 2006.

Melinda Linstad testified she retired seven months earlier as a cheerleader for the New England Patriots, and eventually took a part-time accounts payable job to support the family.

On the morning of Sept. 5, Melinda Linstad began asking her husband about the names of women connected to some of the phone numbers he had contact with late at night, according to Conway. She began dialing the numbers of two of the women, and her husband asked her not to, saying he worked on a fundraiser with one of them, Conway said.

Melinda Linstad was using her husband’s phone while calling the women, and her husband demanded it back before he grabbed her in a bear hug, according to Conway.

Wilson questioned Melinda Linstad’s claims about whether she was truly afraid of her husband. He told jurors that right after the alleged assault she called her mother, but then asked her husband to join her downstairs to review some bills together on the computer.

Wilson suggested to jurors that the injuries on Melinda Linstad’s body were not consistent with what she reported to police — and that she had vowed to ruin her husband.

“(She said) ‘You ruined my life and I am going to ruin yours.’ And here we are,” Wilson told the jury.

Nathan Linstad could face up to a year in county jail if he is convicted by a jury. The trial is expected to last for at least two days, and include testimony from Raymond police, a Manchester police sergeant and the deputy chief medical examiner.